This is a proposal to study the biochemistry and pharmacology of the retina with particular emphasis on cyclic nucleotides. The overall aim of this project is to define the role of adenosine 3',5' monophosphate (cyclic AMP) and guanosine 3',5' monophosphage (cyclic GMP) in retinal function and metabolism. By using quantitative histochemical techniques, we propose to localize and characterize cyclic AMP and cyclic GMP systems in mouse, rabbit, cat and ground squirrel retina. A second specific goal is to define the physiologic and pathologic mechanisms regulating cyclic AMP and cyclic GMP in retina. Understanding the roles of cyclic AMP and cyclic GMP will help explain some of the molecular mechanisms underlying visual processes in the retina.